Hi mate, I'm not an expert on this - but I can tell you how I go about playing BLIC online

If you have the PC version just open gamespy arcade (do not have BLIC running at this stage) - click on BLIC07/RPIC07 and enter the lobby. In the lobby there is a list of players on the bottom right of screen and this list displays what status they are currently in ie, ingame, setting up room, chatting etc.
At the top centre of the screen is a list of current match rooms. If there is a free space (player icon not filled in green) then you can enter the match room and talk with the host. Then simply press "i'm ready icon" the game will automatically launch. Give it a few moments to load up and then pick your team. A green icon then should light up beside your name. Wait for the host to pick their team and then the match will start.
Alternatively you can be a host and set up your own Match room in Gamespy Arcade (set options like number of players etc). Then when somebody enters the match room click "i'm ready" and then click "launch game" the game should then automatically start and load up. Pick what tournament mode you want to play, set the difficulty, number of overs etc. Then do the same as i said before - pick your team - then after other player has chosen team you can start the game.
Hope this works for you - good luck mate
On-line games are really good craic!!